Sigma announced a telephoto macro lens optimized for use with digital cameras.

The Sigma 180mm f3.5 APO EX DG lens has a life-sized reproduction ratio and is an HSM model, which guarantees fast and silent auto focusing as well as full time manual focus. It is compatible with Sigma, Canon, Nikon-D, Pentax and Konica Minolta D-SLRs and will be priced £549.

According to the company, the new multi-layer lens coating reduces flare and ghost, which is a common problem with digital cameras. Two SLD (special low dispersion) glass elements ensure high optical performance for film SLR cameras as well as digital SLR cameras.

The floating inner-focus system features two moving lens groups, which ensures that the lens's physical length remains unchanged. This design also maintains excellent correction for Spherical Aberration and Astigmatism, and provides extremely high optical performance throughout its entire focus range.

The HSM models Sigma, Nikon-D and Canon provides fast, silent AF function as well as full- time manual focus. The lens also features a Focus Limiter Switch, which provides a more efficient and positive AF function. The 1.4x EX teleconverter allows the photographer to use the new APO 180 F3.5 EX DG HSM lens as a 252mm F5 lens (Auto Focus is available between infinity to 1.2m with Canon, Sigma and Nikon mounts only. For macro work at distances closer than 1.2m the lens automatically changes to MF mode. The 1.4x EX teleconverter can only work in MF mode for Minolta and Pentax cameras. If 2X EX teleconverter is attached , this lens can be used as 360mm F7 MF for all mounts.